X2 I also had a set of hooker headers do this also....I had forgotten about it until TooManyReels mentioned itYou might find out that its not the gasket, but the weld on the inside of the header tube has cracked or come loose..I have had two sets of Hookers Headers where the weld has crack inside the number 1 and 3 cylinder and needed to be rewelded...
To confirm this a few weeks back. I took the header loose and ran my finger inside the tube only to find out what I had expected, the weld to metal flange had seperated or cracked...I filled it full of high temp silcone and that has corrected the problem for the short term..
We had that happen to...with a radical small block it sounds like the world is coming to an end. We just welded the headers a bit they were almost to thin but no problems ever with metal gaskets they are the best and IMO the only way to go:yes:X2 I also had a set of hooker headers do this also....I had forgotten about it until TooManyReels mentioned it